Apparatus and method of molding composite foam molding element and composite foam molding element obtained by the same

ABSTRACT

A top side member  4  is attached to the side of one die  2  of a cavity  6  between a pair of dies  2  and  3,  and a back side member  5  is attached to the side of the other die  3.  A charge space is provided between these top and back side members  4  and  5.  Raw material beads each made of a foam resin are supplied between the charge space, air is discharged from a plurality of work piece nozzles provided at the side of the die  3,  and raw material beads are charged. At this time, air discharging is started from a work piece nozzle a 41  set at the most distant position from a charger  61  for supplying raw material beads. Air is charged while the air is discharged sequentially up to the work piece nozzle a 21  set at the most proximal position as the raw material beads are charged. Then, the raw material beads are heated to be foamed and fused, and the top and back side members  4  and  5  are integrated with each other via the foam member  8.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an improved apparatus and methodof molding a composite foam molding element having a top side member anda back side member integrated with each other via a foam member and anovel composite foam molding element obtained by the same.

[0003] 2. Description of the Related Art

[0004] Conventionally, as a method of manufacturing a composite foammolding element having a top side member and a back side memberintegrated with each other via a foam member, there is adopted a methoddescribed in Japanese Patent Application Laid-open Nos. 4-344227 and6-210753.

[0005] A general description of a molding apparatus used by this methodwill be given with reference to FIG. 8. First, a space 16 for molding afoam member is formed between a bottom face of an upper die 11 and a topface of a lower die 15. Then, the top face of the lower die 15 is formedof an air ventilation porous member 18. A skin 17 attached to thesurface is pressure-reduced from a lower discharge space 19, whereby theskin can be adsorbed by and fixed to the top face of the lower die 15.In addition, the inside of the upper die 11 is divided into a left steamchamber 11 a comprising a left steam pipe 11 c and a right steam chamber11 b comprising a right steam pipe 11 d. A ventilation hole 12 a and araw material bead supply pipe 13 a are disposed at the bottom face ofthe left steam chamber 11 a. Similarly, a ventilation hole 12 b and araw material bead supply pipe 13 b are disposed at the lower face of theright steam chamber 11 b.

[0006] In a molding method using such apparatus, the skin 17 is disposedwhile the skin is adsorbed by a ventilation porous member 18. Next, basematerial 14 is disposed at the lower face of the upper die 11 to ensurethe upper and lower dies are closed, and a space 16 for forming a foammember is provided. In this case, at the base material 14, there areprovided through holes 14 a 14 d, 14 a and 14 b that correspond to theventilation holes 12 a and 12 b and openings of the raw material beadsupply pipe 13 a and 13 b, respectively. Here, raw material beads arecharged in the space 16 through the raw material bead supply pipes 13 aand 13 b while charging air is supplied. In this case, however, thesteam chambers 11 a and 11 b maintain pressure reduction withoutsupplying a steam, and discharge the air in the space 16 through theventilation holes 12 a and 12 b. In this way, the charging air suppliedtogether with raw material beads is forcibly discharged, and only theraw material beads can be left and charged in the space 16.

[0007] However, in this molding apparatus, 12 a and 12 b are operated topressure reduction at the same time. Thus, raw material beads are hardlycharged at the periphery in the space 16. Moreover, in the case wherethe thickness of this space 16 is small, and an area is large, inparticular, partial occlusion occurs during charging, and the rawmaterial beads hardly reach a portion distant from the through holes 14a and 14 b of the raw material bead supply pipes 13 a and 13 b. As aresult, non-uniform charging unavoidably occurs.

[0008] In addition, as the molding method using this apparatus, therehas been adopted a heating method in which heating steams are suppliedsequentially from the left steam pipe 11 c of the upper die 11 to theleft steam chamber 11 a, and then, to the steam hole 12 a, and thecharged raw material beads are heated, and then, is sequentiallysupplied from the ventilation hole 12 b to the right steam chamber 11 b,and then, to the right steam pipe lid, and is discharged. However, insuch heating method, there occurs a tendency that the flow of theheating steam in the space 16 short-passes between the closestventilation holes 12 a and 12 b. Thus, in a case shown in FIG. 8,although fusion advances at the center portion, there occurs a deviationthat fusion is delayed at a portion close to the right and left ends. Asa result, there has been a serious problem that non-uniform quality ingravity, appearance, and strength of products occurs.

[0009] In addition, when a skin, base material, and a foam member arediscussed from the aspect of material, for example, in a conventionalcombination used in a dashboard of an automobile, vinyl chloride,polypropylene, and urethane are used for the skin, back side member, andfoam member, respectively, and the top and back materials are integratedin contact with each other. In recent years, there has been a growingneed for causing each part of the skin, base material, and foam memberto be formed of a material with the same components, making it possibleto ensure recycling. From this point of view, technological developmentin which an olefin based elastomer (TPO) is extensively used for a skin,and an olefin based polypropylene foam (ERP) is extensively used for afoam member becomes an important task. The foregoing documents describethat a polypropylene based or polyethylene based sheet, afiller-containing solid resin, a foam resin bead or the like is used asan olefin based resin material for skin 17, base material 14, and foammember. However, with this method as well, it has been extremelydifficult to uniformly manufacture a thin, composite foam moldingelement in different elongated shape having its comparatively smallthickness, large area, and irregularities and curves, as is the casewith a drain pan member of an air conditioner or a dashboard of anautomobile, for example.

[0010] Further, in the conventional method, ventilation holes 12 a and12 b for pressure reducing or steam supply are disposed with intervalsof 25 mm to 50 mm, and correspondingly, through holes 14 c and 14 d areprovided at the base material 14. Thus, there has been problems withhigher die processing and assembling costs and lower strength of acomposite foam molding element caused by the lowered strength of thebase material 14.

[0011] Therefore, it is an object of the present invention to provide amolding apparatus and method for improving the uniformity of rawmaterial beads charged in a cavity for molding a foam member in moldingtechnique for integrating the top and back side members with each othervia a foam member and molding these members, and improving theuniformity of heating and fusion of these charged raw material beads,the molding apparatus and method capable of manufacturing a thin,composite molding element in different elongated shape having itscomparatively small thickness, large area, and irregularities and curvesthat has been hardly manufactured in the conventional techniques.

SUMMARY OF THE INVENTION

[0012] The present invention has been made in order to solve theforegoing problem. According to the present invention, there is providedan apparatus of molding a composite foam molding element for integratinga top side member and a back side member with each other via a foammember and molding these members, the apparatus comprising: forming oneof a pair of dies accompanying a top side member, capable of die closingand opening to form a cavity for foam molding; forming the other die soas to accompany a back side member; arranging a charger for supplyingraw material beads made of a foam resin at a die at the side of the backside member; disposing a plurality of work piece nozzles whose openingsare opened at the cavity; and dividing these work piece nozzles into aplurality of groups, each of which being connected to a work piecesupply device.

[0013] In addition, according to the present invention, there isprovided a method of molding a composite foam molding elementcomprising: attaching a top side member to one die side of a cavitybetween a pair of dies capable of die closing and opening to form acavity for foam molding and a back side member to the other die side;providing a charging space between these top and back side members; thensupplying raw material beads made of a foam resin to this chargingspace; and at the same time, discharging the beads from a plurality ofwork piece nozzles provided at the side of the die having the back sidemember disposed; starting discharging from a work piece nozzle set atthe most distant position from a charger for supplying raw materialbeads when the raw material beads are supplied; charging the rawmaterial beads in accordance with the charging process of sequentiallyperforming discharging up to a work piece nozzle set at the mostproximal position as the raw material beads are charged; and heatingthese charged raw material beads to cause foaming and fusion tointegrate the top side member and the back side member with each othervia the foam member.

[0014] Following the above charging process, the top and back sidemembers can be integrated with each other via the foam member using apreliminary heating step of supplying a heating steam from one of theadjacent work piece nozzles, and then, discharging the steam from theother nozzle so as to heat the charged raw material nozzles; and aheating step of causing the heating steam to be pressed from all thework piece nozzles so as to heat and fuse the charged raw materialbeads. Following the heating step, cooling water is supplied between thetop or back side member and an interior face of a die, and the die andcomposite foam molding element are directly cooled, thereby making itpossible to increase a cooling speed.

[0015] The composite foam molding element of the present invention isobtained by the above molding method. The composite foam molding elementhaving the top and back side members with each other via the foam memberis characterized in that the diameter of a work piece through holeprovided at a position at which a nozzle opening is seen during molding,of a back side member arranged at the side of a side having work piecenozzles disposed, is equal to or smaller than 20 mm, and the pitch isset to equal to or greater than five times as long as the diameter.

[0016] According to the present invention, in integral molding of acomposite foam molding element made of the top and back side members andthe foam member that is a core material, the uniformity when charging orheating and fusing raw material beads is improved, and a failure such asnon-uniform charging or foaming can be eliminated. In particular, athin, composite foam molding element in different elongated shape havingits comparatively small thickness, large surface area, andirregularities and curves can be manufactured without qualitynon-uniformity and lowered strength, making it possible to ensureequipment cost reduction.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a sectional view of a molding die illustrating a moldingapparatus according to the present invention;

[0018]FIG. 2 is a perspective view of essential parts showing a rearface of a back die of the molding apparatus according to the presentinvention;

[0019]FIG. 3 is a view showing a piping system of the molding apparatusaccording to the present invention;

[0020]FIG. 4 is an illustrative view showing the steps of the chargingprocess in the present invention;

[0021]FIG. 5 is a perspective view of essential parts illustrating acomposite foam molding element according to the present invention;

[0022]FIG. 6 is a sectional view showing a molding die for implementinga specific cooling method;

[0023]FIG. 7 is a perspective view showing the molding die shown in FIG.6; and

[0024]FIG. 8 is a sectional view of a molding die illustrating aconventional molding method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, preferred embodiments of the present invention willbe described. In the present embodiment, a composite foam moldingelement configuring a drain pan member for air conditioner is molded.First, a top side member and a back side member each made of apolystylene based resin are provided. The top side member configures asurface layer of a finished composite foam molding element. This moldingelement is fabricated by publicly known means to be a sheet material ofabout 0.3 mm to 1.0 mm in thickness comprising a predeterminedappearance, surface texture, flexibility, strength or the like. The backside member is a backup member that burdens mechanical strength of themolding element, and a plate material of about 1.5 mm to 5.0 mm inthickness is used.

[0026] The molding apparatus of the present invention molds a compositefoam molding element integrated by charging, heating, and fusing rawmaterial beads each made of a foam resin in a space between the top andback side members disposed in a die. As shown in FIG. 1 and FIG. 2, afoam molding cavity 6 is formed of a pair of dies 2 and 3 capable of dieclosing and opening. One die 2 (hereinafter, referred to as a top die)accompanies a top side member, and the above mentioned top side member 4is attached to the interior face of the die. The other die 3(hereinafter, referred to as a back die) accompanies a back side member,and the above mentioned back side member 5 is attached to the interiorface of the die.

[0027] A charger 61 for supplying raw material beads each consisting ofa foam resin is arranged at the rear side of this back die 3, and aplurality of work piece nozzles a21, a31, a41, b21, b31, b41, . . . aredisposed so that each nozzle opening is opened at the cavity 6. Inaddition, these work piece nozzles a21 to b41, . . . each are dividedsingly or into a plurality of groups through pipe systems a2, a3, a4,b2, b3, b4, . . . , as shown in FIG. 3. Each nozzle is connected to awork piece supply device (not shown) capable of supplying one or morekinds of work pieces such as exhaust air, heating steam, pressurizationair or drain. A raw material bead through hole 51 and a work piece flowthrough hole 52 are provided at positions that correspond to the charger61 and the openings of a plurality of work piece nozzles a21 of the backside member 5.

[0028] As shown in FIG. 2, a rear face that corresponds to the full faceof the cavity 6 of the back side 3 is segmented into three areas, “a”,“b”, and “c”. Mount holes 6 a, 6 b, and 6 c of the charger 61 areprovided at these areas, respectively. For example, with respect to thearea “b”, one or more work piece nozzles of the group “b” are disposedin a plurality of columns such as work piece nozzles 11 in a firstcolumn, work piece nozzles 21 to 25 in a second column, work piecenozzles 31 to 35 in a third column, and work piece nozzles 41 to 45 in afourth column. Such arrangement applies to the areas “a” and “b” aswell. Of course, the number of areas or the number of columns fornozzles in the present embodiment is provided as a mere example.

[0029] Now, a work piece supply device in the present invention will bedescribed by referring to a piping system of the molding apparatus shownin FIG. 3. Work pieces such as exhaust air, heating steam,pressurization air or drain used for this molding apparatus are suppliedfrom a piping system in order of main supply valve 7 a, server tank 73a, and individual supply valves 71 a, 71 b, 71 c, and 71 d. The suppliedwork pieces are discharged from a piping system in order of individualdischarge valves 72 a, 72 b, 72 c, and 74 d, server tank 73 b, and maindischarge valve 7 b. This applies to the groups “a” and “c” as well.

[0030] Exhaust air or drain is discharged by an exhaust pump, a vacuumpump or a drain pump provided at the discharge side. Heating steam,pressurization air or the like is supplied from a steam generator or anair compressor such as boiler provided at the supply side. In addition,pressure control is performed by each of the valves on the supply anddischarge sides as required. In the present invention, the main supplyvalve 7 a and the main discharge valve 7 b are connected so that thesevalves can be arbitrarily switched to the exhaust pump, vacuum pump ordrain pump for air exhaust or drain; or the steam generator or aircompressor such as boiler for pressurization air.

[0031] In this piping system, divergent pipes of the piping systems b1,b2, b3 and b4 connecting the individual supply valves 71 a, 71 b, 71 cand 71 d to the individual discharge valves 72 a, 72 b, 72 c and 72 dare connected to the work piece nozzles of each column. Therefore, inthis embodiment, operations such as pressurization or pressure reducingas well as opening and closing operation for supplying work pieces canbe controlled in columns relevant to each work piece nozzle.

[0032] An arrangement of the piping system is not limited thereto.Arrangements such as disposition of groups, the number of chargers orwork piece nozzles belonging to each group or columns in each group maybe adopted in the most efficient combination, depending on the shape,material, or molding conditions for the molding objects. For example, inFIG. 2 and FIG. 3, although work pieces are controlled in two stages,i.e., in units of groups and columns, the piping system is furthersegmented, thereby making it possible to control work pieces in units ofa single work piece nozzle.

[0033] Now, a method of molding a composite foam molding element usingthe molding apparatus of the present invention will be described indetail with reference to FIG. 1 and FIG. 4.

[0034] A first method is characterized by the charging process. A basicoperation is described below. First, as shown in FIG. 1, a top sidemember 4 is disposed at the side of a top die 2 of a cavity 6 between apair of dies 2 and 3, and a back side member 5 is disposed at the sideof a back die 3. Next, a charge space is provided between these top andback side members 4 and 5. Then, raw material beads each made of a foamresin is supplied to this charge space together with charge air.Further, air is exhausted from a plurality of work piece nozzles a21 toa41 and b21 to b41 provided at the side of the die 3 having the backside member 5 disposed, and raw material beads are charged. One of theimportant features in this charging process is that, in exhaustingoperation of the work piece nozzles, air exhaust is started from a workpiece nozzle (work pieces a41 and b41 in FIG. 1) set at the most distantposition from the nozzle tip end of the charger 61, and air exhaust isperformed sequentially up to a work piece nozzle (work piece nozzles a21and b21 in FIG. 1) set at the most proximal position as raw materialbeads are charged. A detailed description will be given by exemplifyinga combination between the charger 61 and the work piece nozzles a21,a31, and a41.

[0035] Step (1): Of the work piece nozzles a21, a31, and a41, the workpiece nozzle a41 that is the most distant from the charger 61 is placedin an exhaust state, and the frontal work piece nozzles a21 and a31 areturned OFF to stop operation. Then, the raw material beads carried froma raw material tank (not shown) at a carrying pressure are supplied to acharge space 63 from the charger 61 with a charge air 62. In this case,the raw material beads are accumulated in the vicinity of an end atwhich the work piece nozzle a41 of the charge space 63 is positioned.

[0036] Step (2): Next, the supply of the raw material beads istemporarily stopped, a pressure is applied to the raw material beads inthe vicinity in which the work piece nozzle a41 is positioned by thesupply of the charge air 62, and an additional pressure for acceleratingcharge is applied.

[0037] Step (3): The work piece nozzle a31 is turned ON to be placed inan exhaust state, and the supply of raw material beads is restarted tocontinue charging, and the raw material beads are accumulated in thevicinity in which the work piece nozzle a31 is positioned.

[0038] Step (4): As in the step (2), an additional pressure is appliedto the raw material beads charged in step (3).

[0039] Step (5): A work piece nozzle a21 is turned ON to be placed in anexhaust state (at this stage, all the work piece nozzles are turned ON).In addition, the supply of raw material beads is restarted to continuecharging, and the raw material beads are accumulated from the work piecenozzle a21 to a position of the charger 61.

[0040] At each of these steps, with respect to the accumulated rawmaterial beads, the exhaust of the distant work piece nozzles iscontinued. Thus, charging is serially advanced, and the entire chargingdensity increases.

[0041] The step (6) is a blow back step in which the pressure of thecharge air 62 and the carrying pressure of the raw material beads arereversed, and the raw material beads in the charger 61 and the carryingpipe are fed back to the raw material tank side.

[0042] The foregoing description is briefly given by exemplifying acombination of the charger 61 and the work piece nozzles a21, a31 anda41. Of course, the present invention is applicable to a variety ofindividual work piece nozzles in each of the groups “a”, “b”, and “c”.That is, each of the individual supply valves 71 a to 71 d and dischargevalves 72 a to 72 d is controlled, charging operation is performed inunits of individual nozzles and in units of columns each consisting of aplurality of nozzles, whereby the charging process corresponding to theshape of a desired composite foam molding element can be adopted. Aftercharging, the charged raw material beads are heated, foamed, and fused,and then, the top side member 4 and the back side member 5 areintegrated with each other via the foam member, whereby a composite foammolding element can be obtained.

[0043] Now, a second method characterized by the heating and fusingprocess of the method of molding the composite foam molding elementaccording to the present invention will be described here.

[0044] This method performs the above mentioned charging process,followed by the preliminary heating step and the heating step. That is,the preliminary heating step supplies heating steam from one work piecenozzle (for example, work piece nozzle a31 in FIG. 1) of the adjacentwork piece nozzles, exhausts air from the other work piece nozzle(nozzles a21 and a41 in FIG. 1), distributes the heating steam, andheats the charge raw material beads. In addition, the heating steppressurizes the heating steam from all the work piece nozzles (workpiece nozzles a21, a31 and a41 in FIG. 1 in the previous example), andheats and fuses the entire charge raw material beads. Hence, the uniformheating and fusing process free of temperature non-uniformity can beimplemented, and the top side member and the back side member can beintegrated with each other via the foam member.

[0045] This method is applicable to a piping system shown in FIG. 3.That is, a heating steam is supplied from a main supply valve 7 a, amain discharge valve 7 b is connected to the exhaust system to be set soas to remove the waste steam. Each of the supply valve and dischargevalve is controlled for each of the work piece nozzle groups such asgroups “a”, “b” and “c”, and the heating and fusing process includingthe preliminary heating step and the heating step can be applied inunits of individual nozzles or in units of the foregoing columns.

[0046] With respect to the length of the path of a heating steam passingthrough the inside of the charge raw material beads, in the case of aconventional method, long and short paths coexist, and a significantdispersion occurs with a heat rate applied to the charge raw materialbeads, and the resultant temperature non-uniformity causes the fusionnon-uniformity of the foam molding element. However, according to theheating and fusing process of the present invention, the distributionpath of the heating steam communicates between the adjacent work piecenozzles. Therefore a distance is comparatively short and uniform, andthus, dispersion becomes small under the heating conditions and thefusion non-uniformity of the foam molding element is significantlyimproved.

[0047] Further, in the preliminary heating step, the distributiondistance of the heating steam is reversed conveniently without beingfixed to a single direction, and further, repeats reversal, therebymaking it possible to further restrict heating non-uniformity. As aprevious stage of the preliminary heating step, a method for adding thestep of supplying a steam at a temperature equal to or smaller than thefusion temperature to exhaust the air in the charge space, and then,internally filling the steam in advance is preferable because the airthat is an obstacle of foaming the raw material beads can be removed,and uniform heating at the later stage can be effectively performed. Inthis case, air may be supplied or exhausted between the work piecenozzles distant from each other, for example, between the work piecenozzles a21 to a41.

[0048] The apparatus and method of molding the composite foam moldingelement according to the present invention are characterized by theabove mentioned points. The apparatus and method are used to effectivelyrestrain charging non-uniformity, heating non-uniformity, and fusionnon-uniformity. When any of the top and back side members and rawmaterial beads used there is made of a synthetic resin made of the samecomponents, the raw material beads form a foam molding element in theprocess of heating and fusing the raw material beads. At the same time,the entirety can be integrated by fusion with the top and back sidemembers. Thus, the molding method and apparatus can be particularlypreferred.

[0049] Further, in a structure comprising a conventional chamber, it hasbeen necessary to dispose a core bent for supplying and discharging avariety of work pieces at a full face of a die with pitches of 25 mm to40 mm. However, in the case of the work piece nozzles according to thepresent invention, the foregoing charging operation or heating andfusing operation is possible. Pitches of 100 mm to 200 mm can be set,and the number of dispositions is about {fraction (1/10)} of theconventional number of dispositions. Thus, the die assembling andprocessing costs can be significantly reduced, and is advantageous fromthe aspect of equipment cost.

[0050] Following the above heating and fusing process, a die is cooled,and a composite foam molding element is removed. In a general coolingmethod including blowing cooling water from the rear face of a die, muchtime is required for cooling, and cooling non-uniformity can occur dueto a difference in partial heat capacity of the die. Then, other methodto conduct cooling water between the inner surface of die and the top orback side member as shown in FIG. 6, for directly cooling the die andthe composite foam molding element is also possible. Thus, as shown inFIG. 6, a number of water supply and exhaust openings 9 are provided ata back die 3, water is supplied to a gap 91 between the back side member5 and the back die 3 opposed thereto, and the back die 3 and thecomposite foam molding element are directly cooled. In this manner, thecooling efficiency is remarkably improved, the cooling time can bereduced, and the cooling non-uniformity is eliminated, thus making itpossible to obtain a uniform, composite foam molding element. As shownin FIG. 7, a number of supply and discharge openings 9 are divided intoa water supply side and a water exhaust side. The water supply andexhaust valves connected to these openings are switched for everyappropriate time interval to reverse the water supply and exhaust sides,whereby the flow direction of cooling water can be reversed. Similarly,the water supply openings 9 may be disposed at the top die 2.

[0051] Now, a composite foam molding element according to the presentinvention will be described with reference to FIG. 5.

[0052] The features of the composite foam molding element according tothe present invention are obtained by any of the foregoing methods ofmolding the composite foam molding elements. In the composite foammolding element having the top and back side members 4 and 5 integratedwith each other via the foam material 8, the diameter of each of thework piece distribution holes 52 a and 52 b being present on the plateface of the back side member 5 disposed at the side of the back die 3having work piece nozzles (refer to reference numerals a21, a31 and a41in FIG. 1) disposed, the holes being provided at positions at which thenozzle openings are seen during molding is equal to or smaller than 20mm in size, and the pitches F and D are set to be equal to or greaterthan 5 times as large as the diameter of the hole. In this manner, inthe present invention, the disposition pitch can be set to becomparatively greater relevant to the diameter of the work piecedistribution hole. Thus, even if the work piece distribution holes areprovided, the mechanical strength of the back side member 5 is notlowered. In addition, the composite foam molding element according tothe present invention is small in thickness relevant to a surface area,and can be formed in thin, different elongated shape havingirregularities or curves. Thus, in particular, this molding element canbe preferably used for composite members of the home electronics productdescribed later or interior members of a vehicle such as automobile.

[0053] Further, of the work piece through holes 52 a and 52 b providedat the back side member 5, a mutual interval F of the work piecedistribution hole 52 a excluding the work piece distribution hole 52 bdisposed along the peripheral rim of the composite foam molding element(corresponding to a portion at which the top side member 4 and the backside member 5 are directly superimposed with each other at a terminalend portion 81 of a foam member 8), can be defined in pitches of atleast 100 mm at a portion at which the thickness E of the foam member 8is less than 10 mm, and can be defined in pitches of at least 150 mm ata portion at which the thickness E is equal to or greater than 10 mm.The diameter of the work piece distribution hole 52 a is generally setto about 10 mm. In this embodiment, the mutual pitches of the work piecedistribution holes 52 a are 10 times or more of the diameter in size,and thus, there is no danger that the mechanical strength of the backside member 5 is lowered.

[0054] In addition, the composite foam molding element according to thepresent invention is preferably applied in particular to specific useswhen the thickness of the internal foam member is set under theconditions described below.

[0055] (1) When the molding element is employed as a container, thethickness of the foam member at a site that is 70% or more of thesurface area of the top side member is set to 30 mm or less.

[0056] (2) When the molding element is employed as an exterior heatinsulating member of an air conditioner, an air cleaner, a refrigeratoror the like or a composite element of a home electronic product such asdrain pan member or air cooling duct thereof, the thickness of the foammember at a site that is 70% or more of the surface area of the top sidemember is set to 30 mm or less.

[0057] (3) When the molding element is employed as an architecturalinterior material such as ceiling material, wall material, partitionwall face material or floor material, the thickness of the foam memberat a site that is 90% or more of the surface area of the top side memberis set to 100 mm or less.

[0058] (4) When the molding element is employed as an interior memberused for an interior portion a vehicle such as automobile, including asdoor trim, glove box, trunk room, installation panel or ceiling, thethickness of the foam member at a site that is 70% or more of thesurface area of the top side member is set to 30 mm or less.

[0059] (5) When the molding element is used as a floor member of avehicle such as automobile, the thickness of the foam member at a sitethat is 70% or more of the surface area of the top side member is set to150 mm or less.

[0060] (6) When the molding element is used as a shock absorbing membersuch as bumper of a vehicle such as automobile, the molding element isformed in thick blocks when the entire top side member is expanded invertical direction relevant to longitudinal direction, and the thicknessof the foam member at a site corresponding to its top is set to 500 mmor less.

[0061] As has been described above, the composite foam molding elementobtained by the improved molding apparatus and method according to thepresent invention is provided at a low cost as a large sized memberbeing excellent in design properties, elasticity touch properties, heatinsulation properties, sound absorption properties, strength of boardmaterial or production cost, the member being free of dispersion inquality. In particular, this material is particularly useful as acomposite element of a home electronics product, an interior member of avehicle such as automobile or architectural interior material listedbelow.

[0062] (1) Composite elements of home electronics product: For example,exterior heat insulating member of air conditioner, air cleaner,refrigerator or the like or functional member of internal drain panmember, air cooling duct member or the like

[0063] (2) Interior member of vehicle such as automobile: For example,interior members such as door trim, glove box, trunk trim, andinstrument panel. Elongated members such as shock absorption member. Inparticular, this use is effective in cost reduction of large-sized partsbecause a large area is made available by integral molding.

[0064] (3) Architectural interior material: For example, excellentamenity can be provided in the fields of ceiling materials, wallmaterials, and floor materials applied in a conventional synthetic resinproduct.

What is claimed is:
 1. An apparatus of molding a composite foam moldingelement for integrating a top side member and a back side member witheach other via a foam member and molding these members, the apparatuscomprising: forming one of a pair of dies accompanying a top sidemember, capable of die closing and opening to form a cavity for foammolding; forming the other die so as to accompany a back side member;arranging a charger for supplying raw material beads made of a foamresin at a die at the side of the back side member; disposing aplurality of work piece nozzles whose openings are opened at the cavity;and dividing these work piece nozzles into a plurality of groups, eachof which being connected to a work piece supply device.
 2. An apparatusof molding a composite foam molding element as claimed in claim 1,wherein said work piece nozzles are connected to a work piececontroller, the nozzles being capable of supplying one or more kinds ofwork pieces such as exhaust air, heating steam, pressurization air,vacuum, cooling water or drain.
 3. A method of molding a composite foammolding element comprising: attaching a top side member to one die sideof a cavity between a pair of dies capable of die closing and opening toform a cavity for foam molding and a back side member to the other dieside; providing a charging space between these top and back sidemembers; supplying raw material beads made of a foam resin to thischarging space; discharging air from a plurality of work piece nozzlesprovided at the side of the die having the back side member disposed;starting air discharging from a work piece nozzle set at the mostdistant position from a charger for supplying raw material beads whenthe raw material beads are supplied; charging the raw material beads inaccordance with the charging process of sequentially performingdischarging up to a work piece nozzle set at the most proximal positionas the raw material beads are charged; and heating these charged rawmaterial beads to cause foaming and fusion to integrate the top sidemember and the back side member with each other via the foam member. 4.A method of molding a composite foam molding element as claimed in claim3, wherein any of said top side member, back side member, and rawmaterial beads is made of a same resin.
 5. A method of molding acomposite foam molding element as claimed in claim 3 or claim 4,wherein, in said charging process, a supply and charge step ofperforming air exhaust from a work piece nozzle while raw material beadsare supplied from a charger and a pressurization and charge step ofperforming air exhaust from a work piece nozzle while the supply of rawmaterial beads are stopped, and the supply of charge air is continuedare repeatedly performed once or plural times.
 6. A method of molding acomposite foam molding element, wherein, following the charge process asclaimed in claim 3 or claim 5, said top side member and back side memberare integrated with each other via a foam member in accordance with aheating step of supplying a heating steam from one of said work piecenozzles, and exhausting air from the other nozzle so as to heat chargeraw material beads; and a heating step of pressurizing the heating steamfrom all the work piece nozzles so as to heat and fuse charge rawmaterial beads.
 7. A method of molding a composite foam molding elementas claimed in any of claims 3 to 6, wherein, following the heating andfusing process, cooling water is supplied between a top or back sidemember and an interior face of a die, and the die and composite foammolding element are directly cooled.
 8. A composite foam molding elementhaving a top side member and a back side member integrated with eachother via a form member, said element obtained by a method of molding acomposite foam molding element as claimed in any of claims 3 to 6,wherein the diameter of a work piece distribution hole provided at aposition at which a nozzle opening is seen during molding, of the backside member integrated at the side of a die having a work piece nozzledisposed, is equal to or smaller than 20 mm, and the pitch is set to be5 times or more of the diameter.
 9. A composite foam molding element asclaimed in claim 8, wherein the thickness is thin relevant to an area,and said element in thin, different elongated shape has irregularitiesor curves.
 10. A composite foam molding element as claimed in claim 8 orclaim 9, wherein a respective one of said work piece distribution holesprovided at said back side member, excluding the work piece distributionholes disposed along the peripheral rim of the composite foam moldingelement is defined in pitches of at least 100 mm at a portion of lessthan 10 mm in thickness of the foam member, and said thickness isdefined at a portion of 10 mm or more with pitches of at least 150 mm.11. A composite foam molding element as claimed in claim 8, wherein thethickness of a foam member at a portion that is 70% or more of thesurface area of said top side member is equal to or smaller than 30 mm,and said element is employed as a container.
 12. A composite foammolding element as claimed in claim 8, wherein the thickness of a foammember at a portion that is 70% or more of the surface area of said topside member is equal to or smaller than 30 mm, and said element isemployed as an exterior heat insulating member such as air conditioner,air cleaner, refrigerator or the like or a composite element of homeelectronics product such as drain pan member or air cooling ductthereof.
 13. A composite foam molding element as claimed in claim 8,wherein the thickness of a foam member at a site that is 90% or more ofthe surface area of said top side member is equal to or smaller than 100mm, and said element is employed as an architectural interior materialsuch as ceiling material, wall material, partition wall face material orfloor material.
 14. A composite foam molding element as claimed in claim8, wherein the thickness of a form member at a site that is 70% or moreof the surface area of said top side member is equal to or smaller than30 mm, and said element is employed as an interior member used for aninterior portion of a vehicle such as automobile such as door trim,glove box, trunk room, installation panel, or ceiling.
 15. A compositefoam molding element as claimed in claim 8, wherein the thickness of afoam member at a site that is 70% or more of the surface area of saidtop side member is equal to or smaller than 150 mm, and said element isemployed as a floor member of a vehicle such as automobile.
 16. Acomposite foam molding element as claimed in claim 8, said compositemolding element having a top side member and a back side memberintegrated with each other via a foam member, wherein said top sidemember is formed to be expanded, the thickness of a foam member at itstop is equal to or smaller than 500 mm, and the element is employed as ashock absorption member such as bumper of a vehicle such as automobile.